Production of bioethanol from rice straw by simultaneous saccharification and fermentation of whole pretreated slurry usingSaccharomyces cerevisiaeKF-7

Abstract

Rice straw is one of the most abundant lignocellulosic waste materials worldwide, and it can serve as feedstock for bioethanol production. In this study, ethanol was produced from rice straw by simultaneous saccharification and fermentation (SSF) of the whole pretreated slurry with high solid load. Pretreatment of rice straw using 0.5% (w/w) H2SO4 was performed to increase the efficiency of enzymatic saccharification. Enzymatic saccharification and SSF of the whole pretreated slurry were subsequently performed to evaluate the inhibitory effect on enzymatic saccharification and the final ethanol yield. The result showed that pretreatment was the key for achieving high ethanol yield of the whole pretreated slurry. Rice straw pretreated at 170°C with a solid load of 15% exhibited efficient enzymatic saccharification. By the result of ethanol yields, no inhibitory effect was found when the whole pretreated slurry was subjected to SSF. The ethanol yield of SSF of the whole pretreated slurry was enhanced to 77.3%, compared with the glucose recovery efficiency of enzymatic saccharification of the washed pretreated rice straw, which was 74.4%. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 582–588, 2015